树qu红核的细胞构筑和红核脊髓束的起源

用Nissl法染色和HRP注入树qu脊髓的不同节段,结果表明,树qu红核和上丘高度向吻侧延伸至乳头体内侧核尾端,细胞柱呈梭状,长约3.7mm,最大处直径2mm。它由大(60-100#mu#m)、中(30-50#mu#m)和小型(10-25#mu#m)细胞构成。红核吻段大细胞较多,占60.7%,中尾段中小型细胞多,占71.7%,, 中、小细胞散在分布于大细胞之间。树qu的红核-脊髓束主要由对侧红核大、中和小型细胞发出的纤维组成;红核吻段背侧部,中尾段的腹部、腹中部和腹中背部细胞发出的纤维交叉投射到颈吻段;红核吻、中、尾段的腹部、腹中部和腹中背部细胞发出的纤维还投射到对侧颈尾段;红核中尾段的腹部、腹中部、腹中背部细胞也有纤维交叉投射到腰段;只有红核吻段和尾段少量细胞发出的纤维投射到同侧颈段。

思茅地区咖啡天牛天敌的多样性调查和控制评价

在1994-1997年的调查研究中发现思茅地区拥有丰富的天敌资源。共鉴定出8种主要捕食和寄生于咖啡天牛的天敌,其中蚂蚁类4种、寄生蜂2种。饲养和调查结果显示,黑褐举腹蚁、立毛举腹蚁、间斑举腹姬蜂和蠼螋4种捕食或寄生性天敌,自然种群大、控制能力强,有很大的利用前景。

The decline and impending extinction of the South China tiger

The South China tiger Panthera tigris amoyensis is the rarest of the five living tiger subspecies, the most critically threatened and the closest to extinction. No wild South China tigers have been seen by officials for 25 years and one was last brought into captivity 27 years ago. The 19 reserves listed by the Chinese Ministry of Forestry within the presumed range of the tiger are spatially fragmented and most are too small to support viable tiger populations. Over the last 40 years wild populations have declined from thousands to a scattered few. Despite its plight and occasional anecdotal reports of sightings by local people, no intensive field study has been conducted on this tiger subspecies and its habitat. The captive population of about 50 tigers, derived from six wild-caught founders, is genetically impoverished with low reproductive output. Given the size and fragmentation of potential tiger habitat, saving what remains of the captive population may be the only option left to prevent extinction of this tiger subspecies, and even this option is becoming increasingly less probable. This precarious dilemma demands that conservation priorities be re-evaluated and action taken immediately to decide if recovery of the wild population will be possible.

斜生栅藻中虾青素的积累过程及其光合活性变化

分析了斜生栅藻(Scenedesmus obliquus)在光温(30℃,180μmol/m2·s)胁迫条件下积累虾青素的过程,观察了该过程中细胞形态及细胞光合生理的变化。胁迫条件下,细胞在48h内生成并积累了包括海胆酮、角黄素、金盏花黄素和金盏花红素在内的多种次生类胡萝卜素,并合成了虾青素及其酯。该过程中,细胞形态由两端尖细变得不规则、膨大,原来由4、8个细胞组成的定形群体变为游离的单个细胞或2个细胞组成的群体。藻细胞光合速率在24h内先下降后上升,而后又呈现下降趋势,从34.29μmolO2/mg C

长江天鹅洲故道江豚的集群规模及其时空分布

2 0 0 1年 5月至 2 0 0 2年 4月 ,选择使用岸上定点观察、流动观察和水上流动观察 3种观察方式 ,对长江天鹅洲故道内约 2 0头江豚的集群状况进行了一个周年的监测 ,共观察到江豚集群 5 88次。结果表明 :天鹅洲故道内江豚以集群的方式迁移和活动 ,集群规模从 2— 2 0头不等 ,一般分成 2个 9— 11头规模的亚群体 ,2个亚群体活动范围相对独立 ,其活动主要为D区和H区。每个亚群体又常分成规模较小的核心群体 ,其中 3头集群最多。一年中春、秋和冬季江豚集群状况基本相同 ,而夏季有所

中国胭脂鱼种群的遗传分析

采用RAPD和PCR RFLP技术 ,分析了长江中游两个中国胭脂鱼群体的遗传结构。 50个随机引物进行RAPD分析 ,有 3个引物显示了多态 ,宜昌、金口群体内个体之间的遗传相似度分别为 0 .92 74、0 .931 3 ,群体之间遗传相似度为 0 .90 0 0。 1 2个限制性内切酶分析了两群体线粒体DNAND - 5/ 6基因的限制性片段长度多态性 ,仅内切酶Ncil的酶切图谱显示了多态 ,基因型间的核苷酸序列歧化距离为 0 .2 35 % ,核苷酸多样性为 0 .0 0 4。分析表明 ,长江中游

异源精子诱导稀有鮈鲫的人工雌核发育

用经过紫外线灭活的异源精子启动稀有鮈鲫卵子发育,再经过热休克分别抑制极体排放和第一次卵裂,得到了极体雌核发育和有丝分裂雌核发育的存活个体。通过正交试验确定诱导极体雌核发育的最佳参数为受精后2min、40℃休克处理2min;诱导有丝分裂雌核发育的最佳参数为受精后17min、40℃休克处理2min。雌核发育个体的形态学特征没有显示出受到父本影响的迹象。RAPD分析表明雌核发育个体扩增片段全部来自于母本,没有发现异源父本DNA成分进入稀有鮈鲫基因组的迹象。实验中还发现,鲤×稀有鮈鲫的正常杂交组合能以极低的几率产

蚌科钩介幼虫的比较形态学研究 Ⅱ.六个种幼虫的形态

研究了真柱矛蚌、剑状矛蚌、洞穴丽蚌、角月丽蚌、三角帆蚌、褶纹冠蚌等六种蚌的育儿囊的类型和钩介幼虫的形态，应用光镜及扫描电镜对钩介幼虫的形态结构进行了观察和比较。结果表明，真柱矛蚌、剑状矛蚌、三角帆蚌、褶纹冠蚌的育儿囊为外鳃类同生型，洞穴丽蚌、角月丽蚌的育儿囊为外鳃类四生型；钩介幼虫可分为二类：真柱矛蚌、剑状矛蚌、褶纹冠蚌为有钩型，三角帆蚌、洞穴丽蚌、角月丽蚌为无钩型。一些细微结构在不同种之间也存在着差异。

福尔马林固定云南鲴的DNA提取及其细胞色素b基因序列分析

福尔马林固定云南鲴的ＤＮＡ提取及其细胞色素ｂ基因序列分析ＤＮＡＥＸＴＲＡＣＴＥＤＦＲＯＭＦＯＲＭＡＬＩＮ－ＦＩＸＥＤＸｅｎｏｃｙｐｒｉｓｙｕｎｎａｎｅｎｓｉｓＡＮＤＳＥＱＵＥＮＣＥＡＮＡＬＹＳＩＳＯＦＩＴＳＣＹＴＯＣＨＲＯＭＥＢＧＥＮＥ关键词福尔马林...

武汉东湖南部湖汊的鼓藻类

从1963年9月到1964年12月,作者在武汉东湖南部的湖汊定点采得48号藻类标本,其鼓藻类十分丰富,经鉴定共有20个属,164个种,75个变种和13个变型。其中有2个新种、7个新变种和2个新变型;12个种、25个变种和5个变型是中国的新记录;在四季中出现频率较高的优势种类有11个种和1个变种。在不同季节共6次所采得的鼓藻种类的统计结果得出,在夏季(6月、8月)的种类最多,秋季和冬季(9月、10月、12月)次之,春季(4月)最少。在东湖252个鼓藻类的分类单位中,热带、亚热带类群共有45个,其中的19个是

Headspace solid-phase microextraction with novel sol-gel permethylated-beta-cyclodextrin/hydroxyl-termination silicone oil fiber for determination of polybrominated diphenyl ethers by gas chromatography-mass spectrometry in soil

A simple, sensitive, and accurate method for determination of polybrominated diphenyl ethers (PBDEs) in soil has been developed based on headspace solid-phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS). Permethylated-beta-cyclodextrin/hydroxyl-termination silicone oil (PM-beta-CD/OH-TSO) fiber was first prepared by sol-gel technology and employed in SPME procedure. By exploiting the superiorities of sot-gel coating technique and the advantages of the high hydrophobic doughnut-shaped cavity of PM-beta-CD, the novel fiber showed desirable operational stability and extraction ability. After optimization on extraction conditions like water addition, extraction temperature, extraction time, salts effect, and solvents addition, the method was validated in soil samples, achieving good linearity (r>0.999), precision (R.S.D. < 10%), accuracy (recovery>78%), and detection limits (S/N =3) raging from 13.0 to 78.3 pg/g. (c) 2007 Published by Elsevier B.V.

Gene structure of goose-type lysozyme in the mandarin fish Siniperca chuatsi with analysis on the lytic activity of its recombinant in Escherichia coli

A goose-type lysozyme (g-lysozyme) gene has been cloned from the mandarin fish (Siniperca chuatsi), with its recombinant protein expressed in Escherichia coli. From the first transcription initiation site, the mandarin fish g-lysozyme gene extends 1307 nucleotides to the end of the 3' untranslated region, and it contains 5 exons and 4 introns. The open reading frame of the glysozyme transcript has 582 nucleotides which encode a 194 amino acid peptide. The 5' flanking region of mandarin fish glysozyme gene shows several common transcriptional factor binding sites when compared with that from Japanese flounder (Paralichthys olivaceus). The recombinant mandarin fish g-lysozyme was expressed in E. coli by using pET-32a vector, and the purified recombinant g-lysozyme shows lytic activity against Micrococcus lysodeikticus. (c) 2005 Elsevier B.V All rights reserved.